ugh! going crazy with this video!ADDED VIDEO

I made a youtube video with examples of the children photography I have done. I just used slideshow in lightroom and added the song I wanted and then took forever placing each picture to where I want it so it goes with the song. However... when I upload it to youtube the whole video goes faster and so does the music. This makes the song end before it is done and now none of my pictures go with the song. I'm guessing it might be compressing the file or something but does anyone know how to fix this?

So here is the video. Watch in 720p if you look at the pictures some are old some are new but I picked them all to go with the song. On lightroom the babies are by the lullaby part and Jazz on the roof is by that part ect but on youtube nothing is right cause the pictures go faster than I had them.?Stay Little Tialee Photography - YouTube